Engine control system and a differential vacuum regulator therefor or the like

ABSTRACT

A differential vacuum regulator having a housing provided with an inlet for being interconnected to a vacuum source and an outlet for being interconnected to a vacuum operated device, valve means being carried by the housing for interconnecting the inlet and the outlet together to provide a certain vacuum level at the outlet when the regulator senses a temperature below a certain temperature and for interconnecting the inlet and the outlet together to produce a different vacuum level at the outlet when the regulator is sensing the certain temperature.

This application is a divisional application of copending parentapplication Ser. No. 672,593, filed Apr. 1, 1976, now U.S. Pat. No.4,108,372.

This invention relates to an improved vehicle engine control system andto a differential vacuum regulator for such a system or the like.

It is well known that in a pneumatic spark timing system for anautomobile engine or the like, it is desired that at a predeterminedtemperature of the engine, the vacuum being transmitted to thedistributor vacuum actuator should be reduced below the manifold vacuuma certain amount as a step function so that there will be a shift in thespark timing to prevent overheating of the engine.

In the past, such spark timing adjustment was accomplished by utilizinga vacuum reducing valve and a thermal selector valve, the vacuumreducing valve receiving manifold vacuum as an input and delivering anoutput of the manifold vacuum minus 1.5 inches Hg. This reduced vacuumoutput and the unreduced manifold vacuum where both piped to a three-waythermal selector valve which selected one of the two, typically theunreduced manifold vacuum, at engine coolant temperatures below 220° F.and the other of the two, the manifold vacuum minus 1.5 inches Hg, atengine coolant temperatures above 220° F., and directed the selectedvacuum source to the distributor. This resulted in a shift in the sparktiming at 220° F. to prevent engine overheating.

It is a feature of this invention to combine the functions of both ofthe above devices into one self-contained unit.

In particular, one embodiment of this invention provides a differentialvacuum regulator having a housing means provided with an inlet adaptedto be interconnected to the vacuum manifold of a vehicle engine and anoutlet adapted to be interconnected to the vacuum operated spark timingdistributor means of the vehicle. The housing means carries a valvemeans for interconnecting the inlet and the outlet together to produce acertain vacuum level at the outlet when the regulator is sensing anengine coolant temperature below a certain temperature whereby thedistributor means is operated at one level of operation thereof and forinterconnecting the inlet and the outlet together to produce a differentvacuum level at the outlet when the regulator is sensing the certaintemperature whereby the distributor means is operated at another levelof operation thereof.

Accordingly, it is an object of this invention to provide an improvedvehicle engine system having one or more of the novel features set forthabove or hereinafter shown or described.

Another object of this invention is to provide a differential vacuumregulator having one or more of the novel features set forth above orhereinafter shown or described.

Other objects, uses and advantages of this invention are apparent from areading of this description which proceeds with reference to theaccompanying drawings forming a part thereof and wherein:

FIG. 1 is a perspective view of the improved differential vacuumregulator of this invention;

FIG. 2 is an enlarged cross-sectional view taken one line 2--2 of FIG.1, FIG. 2 schematically illustrating the vehicle engine control systemof this invention.

FIG. 3 is a view similar to FIG. 2 and illustrates the differentialvacuum regulator in another operating condition thereof.

FIG. 4 is a fragmentary cross-sectional view taken on line 4--4 of FIG.2.

FIG. 5 is a view similar to FIG. 2 and illustrates the differentialvacuum regulator in another operating condition thereof.

FIG. 6 is a view similar to FIG. 5 and illustrates the differentialvacuum regulator in another operating condition thereof.

While the various features of this invention are hereinafter describedand illustrated as being particularly adapted to provide a device forcontrolling spark timing of an automobile engine, it is to be understoodthat the various features of this invention can be utilized singly or inany combination thereof to provide a device for other systems asdesired.

Therefore, this invention is not to be limited to only the embodimentillustrated in the drawings, because the drawings are utilized toillustrate one of the wide variety of uses of this invention.

Referring now to FIGS. 1 and 2, the improved differential vacuumregulator of this invention is generally indicated by the referencenumeral 10 and is illustrated in FIG. 2 as being schematicallyinterconnected in an automobile engine control system of this inventionthat is generally indicated by the reference numeral 11 and comprises anengine manifold vacuum source 12 and a distributor vacuum operatedactuator 13 for controlling the spark timing of the engine controlsystem 11 in a manner well known in the art.

The differential vacuum regulator 10 comprises a housing means 14 havingan inlet 15 adapted to be interconnected to the manifold vacuum source12 by a conduit means 16 and an outlet 17 adapted to be interconnectedto the vacuum operated actuator 13 by a conduit means 18. The housingmeans 14 carries a flexible diaphragm 19 that separates the inlet 15from the outlet 17 and cooperates with the housing means 14 to define aninlet chamber 20 on the side 21 of the diaphragm 19 and an outletchamber 22 on the side 23 of the diaphragm 19, the inlet chamber 20being interconnected to the inlet 15 and the outlet chamber 22 beinginterconnected to the outlet 17.

The flexible diaphragm 19 has an opening means 24 passing centrallytherethrough and being adapted to interconnect the inlet chamber 20 andthe outlet chamber 22 together as illustrated in FIGS. 2 and 6 for apurpose hereinafter described.

A movable valve member 25 is carried by the housing means 14 and has adisc-like surface 26 for engaging against the side 23 of the diaphragm19 in the manner illustrated in FIGS. 3 and 5 to close the opening means24 of the diaphragm 19 from the outlet chamber 22 and interconnect thesame to a passage 27 that passes through a stem 28 of the valve member25, the valve stem 28 being disposed for axial movement in a valve seatmeans 29 of the housing means 14 that leads from the outlet chamber 22to a vent or atmosphere chamber 30 formed in the housing means 14 andcontaining suitable filter material 31. Another valve member 32 isdisposed in the chamber 30 and is adapted to open and close the valveseat means 29, the valve member 32 being operatively associated with thevalve member 25 so that the central portion thereof is engageable by theleft hand end of the stem 28 of the valve member 25 to close theleft-hand end of the passage 27 thereof.

In this manner, when a vacuum is produced in the outlet chamber 22 ofthe housing means 14 in a manner hereinafter described and the diaphragm19 is disposed away from the valve member 25 in the manner illustratedin FIG. 2, the vacuum in the chamber 22 is also in the passage 27 of thevalve stem 28 and holds the valve member 32 against the left hand end ofthe stem 28 by the resulting pressure differential across the valvemember 32, the valve member 32 also being seated against the valve seat29 by the resulting pressure differential created across the valvemember 32 between the chambers 30 and 22. However, when the diaphragm 19is moved to the left in the manner illustrated in FIG. 3 by a resultingpressure differential being created across the diaphragm 19 in a mannerhereinafter described, the stem 27 pushes the valve member 32 away fromthe valve seat means 29 to interconnect the atmosphere chamber 30 to theoutlet chamber 22 through the open valve seat 29 and the space betweenthe valve seat 29 and valve stem 28, the valve member 32 remaining onthe left hand end of the valve stem 27 because of the pressuredifferential acting across the valve member 32 because the passage 27 ofthe valve stem 28 is still in communication with the vacuum in thechamber 20 through the opening means 24 of the diaphragm 19. Suchleftward movement of the valve member 26 terminates when the valvemember 26 engages against embossments or ribs 33, FIGS. 2 and 4, formedon the housing means 14 to permit the opened valve seat 29 tocommunicate with the outlet chamber 22 when the valve member 26 has beenmoved against the ribs 33 in the manner illustrated in FIG. 3.

Subsequently, when the pressure differential across the diaphragm 19substantially decreases to zero so that the diaphragm 19 can return tothe position illustrated in FIG. 2 by its natural bias, the valve member26 follows such rightward movement until the valve member 32 seatsagainst the valve seat 29 in the manner illustrated in FIG. 2 wherebythe diaphragm 19 can move away from the valve member 26 in the mannerillustrated in FIG. 2 to interconnect the chambers 22 and 20 through theopening means 24 thereof for a purpose hereinafter described.

A temperature responsive device that is generally indicated by thereference numeral 34 is carried by the housing means 14 and comprises acylinder section 35 having a movable piston 36 extending out of thecylinder section 35 and being moved to the left in the drawings by asuitable wax-like charge in the cylinder 35 when the device 34 senses acertain temperature, such as 220° F. as will be apparent hereinafter, ina manner well known in the art, the piston 36 contracting into thecylinder 35 when the device 34 senses a temperature below the certaintemperature thereof.

A stem member 37 has an end 38 thereof adapted to bear against an end 39of the cylinder 35 by the force of a compression spring 40 having oneend 41 bearing against an annular flange 42 of the stem 37 and the otherend 43 thereof bearing against a shoulder 44 of the housing means 14,the end 38 of the stem 37 having an opening 45 therein receiving thepiston 36.

The left-hand end 46 of the stem member 37 passes through an opening 47of a spring retainer 48 and is operatively interconnected thereto byoutwardly directed tangs 49 as illustrated. A compression spring 50 isdisposed in the inlet chamber 20 and has one end 51 bearing against thehousing means 14 and the other end 52 thereof bearing against the springretainer 48 whereby the force of the spring 50 tends to move the springretainer 48 toward the side 21 of the diaphragm 19.

However, as long as the temperature responsive device 34 is sensing atemperature below the certain temperature, which in the example of theengine control system 11 is 220° F., the force of the spring 40 isadapted to maintain the spring retainer 48 sufficiently to the right inopposition to the force of the compression spring 50 so that the springretainer 48 does not engage the diaphragm 19 as illustrated in FIGS. 2and 3. However, when the temperature responsive device 34 is sensing thecertain temperature or above, the piston 36 thereof has extendedoutwardly to the left to carry the stem member 37 therewith inopposition to the force of the compression spring 40 to collapse thecompression spring 40 and permit the compression spring 50 to move thespring retainer 48 against the diaphragm 19 in the manner illustrated inFIGS. 5 and 6 to add the force of the spring 50 to the diaphragm 19 fora purpose hereinafter described.

When the temperature being sensed by the device 34 falls below thecertain temperature, the piston 36 collapses into the cylinder 35 andthe compression spring 40 moves the stem member 37 to the right andthereby collapses the compression spring 50 and moves, the springretainer 48 out of engagement with the diaphragm 19 as illustrated inFIGS. 2 and 3 whereby the force of the spring 50 is no longer active onthe diaphragm 19.

From the above, it can be seen that the differential vacuum regulator 10of this invention can be formed in a simple and economical manner tooperate the engine control system 11 of this invention in a manner nowto be described.

With the inlet 15 and outlet 17 of the differential vacuum regulator 10being respectively interconnected to the engine vacuum manifold 12 andthe vacuum operated actuator 13, the spring retainer 48 is maintained tothe right in the drawings by the temperature responsive device 34 aslong as the engine coolant temperature is below 220° F. Thus, the vacuumbeing created in the outlet chamber 22 is substantially the same as thevacuum being created in the inlet chamber 20 because the chambers 20 and22 are interconnected together by the opening 24 in the diaphragm 19whereby the vacuum operated actuator 13 will be operated at one level ofoperation thereof. Should the vacuum in the chamber 22 be greater thanthe vacuum in the inlet chamber 20, the resulting pressure differentialacross the diaphragm 19 will cause the diaphragm 19 to move to the leftas illustrated in FIG. 3 and engage against the valve member 26 todisconnect the opening 24 of the diaphragm 19 from the outlet chamber 22and cause the valve member 32 to open the valve seat 29 and therebypermit atmosphere to seep into the chamber 22 through the open valveseat 29 until the vacuum levels in the chambers 20 and 22 equalize. Whenthe vacuum levels in the chambers 20 and 22 equalize, the diaphragm 19will return to the position illustrated in FIG. 2 whereby the valvemember 32 closes against the valve seat 29 as previously described.

When the engine coolant temperature reaches 220° F. or above, thetemperature responsive device 34 has extended the piston 36 to the leftin the manner illustrated in FIGS. 5 and 6 so that the compressionspring 40 is collapsed sufficiently to permit the compression spring 50to move the spring retainer 48 against the side 21 of the diaphragm 19and add the force of the spring 50 to the diaphragm 19 tending to movethe diaphragm 19 to the left.

In this manner, it requires a lesser vacuum value in the outlet chamber22 than the vacuum value in the inlet chamber 20 to maintain thediaphragm 19 in the neutral position illustrated in FIG. 6 whereby thevacuum value level being directed to the vacuum operated actuator 13 isat a different level than when the spring 50 is rendered inactive orremoved from acting on the diaphragm 19 in the manner illustrated inFIGS. 2 and 3.

In particular, in the example of the engine system 11 of this invention,when the force of the spring 50 is added to the right side 21 of thediaphragm 19 in the manner illustrated in FIGS. 5 and 6, the vacuumlevel in the chamber 22 is now the same as the manifold vacuum chamber20 minus 1.5 inches Hg so that the actuator 13 causes a shift in thespark timing of the engine to prevent overheating thereof.

With the force of the spring 50 being added to the diaphragm 19 in themanner illustrated in FIGS. 5 and 6, should the vacuum value in thechamber 22 be greater than the manifold vacuum minus 1.5 inches Hgpreviously described, the resulting pressure differential across thediaphragm 19 causes the diaphragm 19 to move to the left to open thevalve member 32 and thereby permit the atmosphere to bleed into thechamber 22 to return the diaphragm 19 to the balanced conditionillustrated in FIG. 6 wherein the vacuum value in the outlet chamber 22is the same as the vacuum value in the inlet chamber 20 minus 1.5 inchesHg.

Therefore, it can be seen that by adding the force of the spring 50 tothe diaphragm 19, the spring 50 will create a condition whereby the onlyway that relay balance can be achieved is for the absolute pressure onthe output side of the diaphragm to be higher (less vacuum) than on theinput side. By properly matching the diaphragm area and the bias springload 50, the proper differential can be achieved. However, by removingthe bias spring 50 in the manner illustrated in FIGS. 2 and 3, thevacuum differential is removed so that substantially the same vacuumwill exist on both the input and output sides of the diaphragm 19.Accordingly, the differential vacuum regulator of this invention is sodesigned that the bias spring 50 is "picked up" off of the diaphragm 19at temperatures below 220° F. and allowed to rest on the diaphragm 19 attemperatures above 220° F. The design is such that once 220° F. isreached and the spring load 50 is applied to the diaphragm 19, highertemperatures do not increase the bias load 50 because the stem member 37can be further moved to the left as illustrated in FIG. 5 relative tothe spring retainer 28. Accordingly, no further reduction in the outputvacuum beyond the desired 1.5 inches Hg will take place.

Thus, it can be seen that this invention not only provides an improvedvehicle engine control system, but also this invention provides animproved differential vacuum regulator therefor or the like.

While the form of the invention now preferred has been illustrated anddescribed as required by the Patent Statute, it is to be understood thatother forms can be utilized and still fall within the scope of theappended claims.

What is claimed is:
 1. In a vehicle engine system having a vacuummanifold and a vacuum operated spark timing distributor, the improvementcomprising a differential vacuum regulator having a housing meansprovided with an inlet interconnected to said vacuum manifold and anoutlet interconnected to said distributor, and valve means carried bysaid housing means for interconnecting said inlet and said outlettogether to produce a certain vacuum level at said outlet when saidregulator is sensing an engine coolant temperature below a certaintemperature whereby said distributor is operated at one level ofoperation thereof and for interconnecting said inlet and said outlettogether to produce a different vacuum level at said outlet when saidregulator is sensing said certain temperature whereby said distributoris operated at another level of operation thereof, said valve meanscomprising a temperature sensing device and a flexible diaphragm that isresponsive to the vacuum at said inlet, said diaphragm having an inletside that is exposed to said inlet and having an outlet side that isexposed to said outlet, said valve means comprising a biasing means foracting on said inlet side of said flexible diaphragm and beingcontrolled by said temperature sensing device, said temperature sensingdevice rendering said biasing means inactive by holding said biasingmeans away from said inlet side of said diaphragm when said temperaturesensing device is sensing a temperature below said certain temperatureand rendering said biasing means active by causing said biasing means toengage and act on said inlet side of said diaphragm when saidtemperature sensing device is sensing said certain temperature, saidflexible diaphragm separating said inlet from said outlet and havingopening means therethrough for interconnecting said inlet to saidoutlet, said valve means comprising a valve member for opening andclosing said opening means, said housing means having a valve seatleading from said outlet to the atmosphere, another valve member foropening and closing said valve seat, the first-named valve member beingoperatively associated with said other valve member to open said othervalve member when said first-named valve member has closed said openingmeans of said diaphragm and to close said other valve member when saidfirst named valve member has opened said opening means of saiddiaphragm.
 2. A vehicle engine system as set forth in claim 1 whereinsaid temperature sensing device comprises a piston and cylinder device,the piston of said device being operatively interconnected to saidbiasing means to control said biasing means.
 3. A vehicle engine systemas set forth in claim 1 wherein said valve means tends to producesubstantially the same vacuum level in said outlet that is produced atsaid inlet when said regulator is sensing a temperature below saidcertain temperature.
 4. A vehicle engine system as set forth in claim 3wherein said valve means tends to produce a lesser vacuum level in saidoutlet than is produced in said inlet when said regulator is sensingsaid certain temperature.
 5. A vehicle engine system as set forth inclaim 1 wherein said valve means tends to produce said different vacuumlevel in substantially a constant manner regardless of the sensedtemperature above said certain temperature.